#include <iostream>
#include <vector>
using namespace std;
using ll = long long;
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
ll n, k;
cin >> n >> k;
vector<vector<pair<ll, ll> > > adj(n + 1);
for (ll i = 1; i < n; ++i) {
ll u, v, c;
cin >> u >> v >> c;
adj[u].emplace_back(v, c);
adj[v].emplace_back(u, c);
}
vector<ll> ans;
auto dfs = [&](auto &&self, ll u, ll p, ll cur) -> pair<bool, ll> {
ll acoperit = -1e15, neacoperit = 0;
for (auto &[v, c]: adj[u]) {
if (v == p) continue;
if (auto t = self(self, v, u, c); t.first) {
acoperit = max(acoperit, t.second);
} else {
neacoperit = max(neacoperit, t.second);
}
}
pair<bool, ll> nod;
if (acoperit >= neacoperit) {
nod = {true, acoperit - cur};
} else {
nod = {false, neacoperit + cur};
}
if (!nod.first && nod.second > k) {
ans.push_back(u);
nod = {true, k - cur};
}
if (nod.first && nod.second < 0)
nod = {false, 0};
return nod;
};
dfs(dfs, 1, 0, 1e15);
cout << ans.size() << '\n';
for (const auto &it: ans)
cout << it << ' ';
cout << '\n';
}
/*
9 4
1 2 10
2 3 4
8 9 4
8 7 3
7 3 5
3 4 1
4 5 3
5 6 2
*/
